copy_bio_stat
copy_bio_stat(&stats->bios_in, &vdo->stats.bios_in);
copy_bio_stat(&stats->bios_in_partial, &vdo->stats.bios_in_partial);
copy_bio_stat(&stats->bios_out, &vdo->stats.bios_out);
copy_bio_stat(&stats->bios_meta, &vdo->stats.bios_meta);
copy_bio_stat(&stats->bios_journal, &vdo->stats.bios_journal);
copy_bio_stat(&stats->bios_page_cache, &vdo->stats.bios_page_cache);
copy_bio_stat(&stats->bios_out_completed, &vdo->stats.bios_out_completed);
copy_bio_stat(&stats->bios_meta_completed, &vdo->stats.bios_meta_completed);
copy_bio_stat(&stats->bios_journal_completed,
copy_bio_stat(&stats->bios_page_cache_completed,
copy_bio_stat(&stats->bios_acknowledged, &vdo->stats.bios_acknowledged);
copy_bio_stat(&stats->bios_acknowledged_partial, &vdo->stats.bios_acknowledged_partial);